[ES] Added 3.4

Signed-off-by: Jim Martens <github@2martens.de>

es/blatt3/uebung3-4/uebung3-4.ino

@@ -0,0 +1,121 @@
+#include <Servo.h>
+
+// these variables describe the used hardware pins
+// adjust them when you use other pins
+// hardware pins
+int az = 50;
+
+int xout = A4;
+int zout = A2;
+int vref = A3;
+int ledPin = 13;
+
+// servo
+Servo ourServo;
+int servoPin = 11;
+
+// used to achieve a 10 Hz frequency
+// don't touch them
+long rc = 1049999;
+
+// flags for servo
+bool volatile cwMaxReached = false;
+bool volatile ccwMaxReached = false;
+bool volatile lightLED = false;
+
+bool volatile read_ready = false;
+
+
+/**
+ * Calculates the servo position.
+ *
+ * @param int currentServoPos
+ * @param int rotationZ
+ */
+int calculate_new_servo_pos(int currentServoPos, int rotationZ) {
+    int newServoPos = currentServoPos + rotationZ;
+
+    if (newServoPos > 159) {
+        newServoPos = 159;
+        cwMaxReached = true;
+        lightLED = true;
+    }
+
+    if (newServoPos < 25) {
+        newServoPos = 25;
+        ccwMaxReached = true;
+        lightLED = true;
+    }
+
+    return newServoPos;
+}
+
+/**
+ * Setup function for initial setup code
+ */
+void setup() {
+    pmc_set_writeprotect(false);
+    pmc_enable_periph_clk(ID_TC1);
+
+    // configure hardware timer
+    TC_Configure(TC0, 1, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK2) ;
+    TC_SetRC(TC0, 1, rc);
+
+    TC0->TC_CHANNEL[1].TC_IER=TC_IER_CPCS;   // IER = interrupt enable register
+    TC0->TC_CHANNEL[1].TC_IDR=~TC_IER_CPCS;
+
+    NVIC_ClearPendingIRQ(TC1_IRQn);
+    NVIC_EnableIRQ(TC1_IRQn);
+
+    // start hardware timer
+    //TC_Start(TC0, 1);
+
+    // Configure pins
+    pinMode(ledPin, OUTPUT);
+    pinMode(az, OUTPUT);
+    digitalWrite(az, HIGH);
+    digitalWrite(ledPin, LOW);
+    
+    ourServo.attach(servoPin);
+    ourServo.write(90);
+
+    // initialize serial port
+    Serial.begin(9600);
+}
+
+/**
+ * Loop function for main code
+ */
+void loop() {
+    if (Serial.available() > 0) {
+      char command[8];
+      char currentChar;
+      int i = 0;
+      bool readable = true;
+      while (readable) {
+        currentChar = Serial.read();
+        readable = (currentChar == -1);
+        command[i] = currentChar;
+        i++;
+      }
+      command[i] = '\0';
+      
+      if (strcmp(command, "LED_on") == 0) {
+        digitalWrite(ledPin, HIGH);
+      }
+      else {
+        digitalWrite(ledPin, LOW);
+      }
+      Serial.println(command);
+    }
+}
+
+/**
+ * Used to handle the timer.
+ */
+void TC1_Handler()
+{
+    // request static for some magic behind the curtain
+    TC_GetStatus(TC0, 1);
+    read_ready = true;
+}